Hot-air furnace.



No. 653,927. Patented luly l7, I900.

A. w. CRAM.

HOT AIR FURNACE.

Application filed Oct. 10 189 OOOOOOO UNITED STATES PATENT OFFICE.

- ALONZO W. ORAM, OF HAVERI-IILL, MASSACHUSETTS, ASSIGNOR TO ABBY F.

' CRAM, OF SAME PLACE.

HOT-AIR FURNACE.

SPECIFICATION forming part of Letters Patent No. 653,927, dated July 17,1900.

Application filed October 10, 1899. Serial No. 733,143. (No model.)

To aZZ whom it may concern:

Be it known that I, ALONZO W. CRAM, a citizen of the United States,residing at Haverhill, in the countyof Essex and State of Massachusetts,have invented new and useful Improvements in Furnaces, of whichthefollowing is a specification.

My invention relates to improvements in furnaces, and which is moreespecially intended to be used as a hot-air furnace, though it may beused as a hot-water furnace or as a steam-generator, as may be desired,without departing from the spirit of my invention.

The primary object of myiinvention is to provide a furnace having thegreatest possible heating-surface, whereby a saving of fuel and labor iselfected, and, secondly, to so construct the furnace thatit will operatewithout the aid of the draft of the chimney, which enables me to utilizethe escaping products of combustion for heating purposes in the mosteffective manner.

In the accompanying drawings, Figure l is a vertical perspectivesectional view of a furnace embodying my invention. Fig. 2 is a top planview of the same. tached perspective sectional view of one of thesections of which the heating portion of the furnace is composed.

When the furnace is to be used as a hotair furnace, an outer casing B ofany desired form or style will be used for receiving the air which is tobe used and then conveyed to the desired point or points of a building.Inclosed within this outer casing Bis the heating portion A of thefurnace, which consists of a plurality of radially-arranged sections 'K,which in cross-section are of a truncated the bottom of the chambers Kfor the purpose of forming a passage-way c, and the par- Fig. 3 is adetition a serves to divide the sections K into the inner E and theouter chambers or fines G, both of which have communication with theinterior of the fire chamber or box A, as clearly shown.

The sections K rest upon a horizontal sec tion S, which surrounds theash-pit M beneath the grate H, and the lower end of each of the sectionsK is placed in communication with the horizontal sectionS through themedium of the vertical pipes O.

One of thesections K is provided with an outwardly-projecting pipe X,and the section S is provided with an outwardly-projecting pipe X,through which the said section may be cleaned, and the pipes X and X areconnected through the medium of a vertical pipe X, thusestablishingcommunication between the lower end of the sections Kthrough the pipe 0, section S, and pipes X X, and X to the chimney.Situated in the pipe X, between the section K, to which it is connected,and the upper end of the vertical pipe X, is

a damper N, by means of which direct draft between the upper end of thesections K and the chimney is prevented or admitted, as

may be desired.

In operation when the fire is started the damper is closed and the innerwalls of the chambers or flues E of the sections K are first heated andbecome of course warmer than the outer chambers or fiues G, thus causingan upward current in the chambers E, as indicated by arrow, and adownward current through the chambers or fines G, as also indicated byarrow. In'turn the upward current in the chambers E draws the warm airfrom the upper chambers E, which passes down the said chambers G, warmsthe outer surface or walls thereof, which are in contact with the airwithin the outer casing B, which isto be warmed, the air to be warmedthereby cooling off. to some extent the walls of the flues or chambers Gby giving its heat to the air within the outer casing 13, making the airwithin the flues G heavier, causing it to descend and to pass up throughthe fines or chambers E, thereby keeping up a constant circulationwithout the aidof the draft of the out the lower end of the sections Kinto the horizontal section S, through the pipes 0, as indicated byarrow, and through the pipes X, l and X to the chimney. It will be notedthat the pipes O, which establish communication between the chimney andthe said sections, afford a restricted outlet for the products ofcombustion.

From the above description it will be seen that I have produced a burnerhaving a large heating-surface, thereby radiating the great est possibleamount of heat from a given amount of fuel, and which is so constructedthat circulation will be maintained within the furnace without the aidof the draft of the chimney, which will be found to be a great saving infuel and in the labor of feeding the same to the furnace.

The furnace may be constructed in various ways, depending upon thematerial of which it is composed. It may be made in vertical sectionshaving an air-space through crosssection or whole, as shown in drawings,or it may be made in annular sections, one made on top of the other,with cup-joints for packing to make the space between the sections gasand air tight, and the sections may be of any desired number. For makinga combi nation-furnace one or more sections may be used for hot water orsteam, while the others are used for hot air, and the top of thefirechamber A is closed with a suitable trap J to separate the top ofthe fuel-chamber from the warm-air space or chamber, as will be readilyunderstood.

The construction herein shown and described may be equally adapted to beused either as a gas or oil heating radiator for warming a room, withthe advantage of a large heating-surface, the oil-heater taking theplace of the grate within the fire-pot A, and the circulation will bethrough the several sections in the manner before described.

Having thus described my invention, what I claim, and desire to secureby Letters Patent, is

1. A furnace consisting of a plurality of separate vertically-arrangedchambers the inner walls of which constitute a fire pot or chamber, saidchambers divided into two vertical fiues having separate communicationsat their upper ends with the fire-pot and communicating with each otherat their lower ends, substantially as described.

2. A furnace comprising a plurality of radially-arranged separatevertical sections the inner walls of which constitute a fire pot orchamber, the upper ends of the sections having openings in communicationwith the upper end of the fire-pot, and each section provided with avertically-arranged partition having its upper end turned inward to constitute two separate flues in each chamber having separatecommunications with the upper end of the fire-pot, the lower end of thepartitions being above the lower end of the sections forming apassage-way establishing communication between the lower end of the twoseparate flues, and a communication be tween the sections and thechimney, substantially as described.

3. A furnace comprising a plurality of vertically and radially arrangedsections, said sections being of a triangular truncated shape incross-section and the truncated ends of the sections forming the wallsof a fire-pot, the upper ends of the sections provided with an openinghaving communication with the up per end of the fire-pot, each sectionhaving a vertically-arranged partition with its upper end turnedhorizontally and dividing the openings in the sections into two separatepassage-ways,and the lower ends of the partitions stopping at a pointabove the lower end of the sections constituting a passage-way formingcommunication between the lower ends of the fines formed by saidpartition, the lower end of the sections having a chimney communication,substantially as described.

4. A furnace comprising a plurality of vertical radially-arrangedseparate chambers, the inner walls of which constitute a fire-pot, theupper ends of the chambers having openings communicating with the upperend of the fire-pot,each chamber having a verticallyarranged partitiondividing the sections into two separate flues, the lower ends of thepartitions stopping at a point above the lower ends of the sections toform a communicating passage-way and the upper ends of the partitionsturned inward to form separate passage-ways and communication.respectively with the upper end of said lines, a horizontal section atthe lower end of the said vertical sections, and communications betweenthe lower ends of the vertical sections and the horizontal section, andthe horizontal section provided with a chimney commu-' ends with theupper end of the fire-pot, apipe X having'eommunication at one end withone of said vertical sections, a vertical pipe having communication withthe said pipe X and fines communicating with each other, substantiallyas described.

'7. A furnace comprising a fire-pot, tines vertically arrangedtherearound in pairs, one flue of each pair being adjacent the fire-potand the other fine of each pair being removed therefrom, said fineshaving separate communications with the upper end of the fire pot orchamber, and the lower ends of the said fines having communication witheach other, substantially as described.

8. A furnace comprising a fire pot or chamber, flues vertically arrangedtherearound in pairs, the inner fines of the said pairs being adjacentthe fire-pot and the other fines of the pairs being removed therefrom,the upper ends of the said fines having separate communications with theupper end of the fire pot or chamber, the lower ends of the fines beingin communication with each other, and a communication common to thelower ends of the fines and the chimney, substantially as described.

9. A furnace comprising a plurality of radially-arranged separatevertical chambers the inner walls of which constitute a fire pot orchamber, each chamber divided into two vertically arranged fines havingseparate communications at their upper ends with the upper ends of thefire pot or chamber, the lower ends of the fines being in communicationwith each other, and a comparatively-restricted communication betweenthe lower ends of all of the flues and the chimney, substantially asdescribed.

In testimony whereof I have hereunto set my hand in the presence of twosubscribing witnesses.

ALONZO W. CRAM. Witnesses:

CHARLES J. HALPEN, WM. D. CRAM.

